10 DEADLIEST Decisions in Human History

Welcome to WatchMojo, and today we’ll be diving into the history books to review humanity’s worst choices that led to the most tragically lethal outcomes.

Escalating U.S. Involvement in Vietnam

The Vietnam War was a smaller part of the Cold War, a period of high tensions between America and the Soviet Union. Following Vietnam’s independence from France in 1954, the country was temporarily split into two: the communist North and the American-backed South. Instead of letting the nation peacefully vote on its government, the U.S. escalated tensions, leading to all-out war in the region. At first, only about 16,000 American troops were stationed in Vietnam. However, following the Gulf of Tonkin[a] incident, President Lyndon B. Johnson dramatically increased military involvement, deploying over 500,000 troops within four years. This decision had devastating consequences, as over 50,000 American service members died, as well as up to three million Vietnamese soldiers and civilians.

Stalin’s Terror Famine

In the early 1930s, Joseph Stalin’s Soviet government engineered a devastating famine in Ukraine, driven not by natural causes but by his brutal policies. These policies were the forced collectivization of agriculture, and unrealistic grain quotas. As a result, Ukrainian farmers were stripped of their food supply, with countless villages being left to starve. Many historians agree that Stalin deliberately used his policies, and the resulting famine, to suppress Ukrainian nationalism. Between 3.5 and five million Ukrainians perished due to the famine, and its impact is still felt in the nation today. It serves as a grim reminder of the horrors of authoritarianism, where leaders prioritize political ambitions over human life with no repercussions.

Insulting Genghis Khan

Most amateur historians are familiar with the Mongolian Empire, but far fewer have heard of the Khwarazmian[b] Empire—and for good reason. The empire became independent in 1190, around the same time Mongolian leader Genghis Khan was rising to power. By 1218, the two empires were on friendly terms. However, that relationship quickly soured when a Khwarazmian governor decided to execute and seize a Mongolian trade caravan that the Khan had sent on a goodwill mission. Genghis was deeply offended by this move and temporarily halted his campaign in China to launch a full-scale invasion of the Khwarazmian Empire. Somewhere between two and 15 million people died, which would now be considered an act of ethnic cleansing.

Mao’s Great Leap Forward

China had a rough time in the 19th century, with Britain forcing opium into their country, and foreign powers scrambling to seize Chinese land. After successfully repelling Imperial Japan in World War II, Mao rose to power with a vision to rebuild his nation. His ambitious plan, the Great Leap Forward, aimed to rapidly industrialize China. Unfortunately, it turned out to be a total disaster, leading to a famine that caused the deaths of 15 to 55 million people. Surrounded by yes men who were too scared to report the failures of his policies, Mao allowed the crisis to persist for four years. By its conclusion in 1962, the Great Leap Forward had only taken the Chinese people ten steps back.

An Lushan[c] Rebellion

Many of humanity’s deadliest events occurred in China, on account of its tremendous size and long history. In 751, during the Tang dynasty, Emperor Xuanzong appointed An Lushan a military governor over three prefectures. This decision ultimately proved to be a major blunder when An Lushan instigated a rebellion in 755, and declared himself emperor. The rebellion lasted eight years, claiming an estimated 13 to 36 million lives in this short time, and leaving entire regions depopulated. This catastrophe marked the end of the Tang dynasty’s golden age. Innocent civilians suffered the most, enduring massacres, starvation, and widespread chaos. Events like this reveal the dangers of unchecked regional power, a recurring issue in China’s history.

Taiping[d] Rebellion

The second Chinese civil war on our list, the Taiping Rebellion began in 1850 and raged on for 14 years. It was sparked by Hong Xiuquan, who believed he was the younger brother of Jesus Christ and founded the Taiping Heavenly Kingdom, what would be considered a cult by today’s standards. This conflict became the deadliest civil war in history, resulting in the deaths of between 20 and 30 million people. Hong’s leadership was erratic and authoritarian, driven by religious fervor. He chose Nanjing as his capital, which led to a siege that crippled the city. It also further weakened the ruling Qing dynasty, paving the way for foreign powers to invade China with ease.

Censorship of Spanish Flu

When the COVID-19 pandemic began, it dominated media coverage. Many may have found this exhausting, but at least, it was preferable to the opposite problem faced during the Spanish flu. In 1918, this deadly strain of influenza triggered a two-year global pandemic, killing between 17 to 100 million people. After World War I, governments enforced strict censorship to boost morale, preventing newspapers from reporting on the flu. Only neutral Spain published news about it, causing many to think the outbreak began there and resulting in the “Spanish flu” misnomer. This also convinced other countries they weren’t at risk, including the U.S., where the virus likely originated. Without accurate information, mass gatherings continued, social distancing and quarantines were neglected, and healthcare systems became severely overwhelmed.

Killing Franz Ferdinand[e]

On June 28th, 1914, Bosnian Serb Gavrilo Princip assassinated Franz Ferdinand, the heir to the Austro-Hungarian throne. This singular act set off a complex chain of events that led to World War I, a conflict that claimed approximately 17 million lives. If Ferdinand wasn’t assassinated, it’s likely the war would have still occurred, due to a combination of complicated geopolitical factors. Still, it undeniably served as a catalyst that accelerated these events. The resulting war lasted four years, and at the time, was the bloodiest conflict in human history. It also facilitated the global spread of the aforementioned Spanish Flu, taking even more lives.

Harsh Terms After World War 1

After winning the First World War, the victors wanted someone to point the finger at. Rather than promoting reconciliation and fostering friendship between nations, they went in the opposite direction. This culminated in the 1919 Treaty of Versailles[f], which placed sole responsibility for the war on Germany, and ignored the larger role nationalism played. The resulting international humiliation fostered resentment in the German people, enabling Hitler and the Nazis to take charge. Seeking revenge, they initiated World War II, the bloodiest conflict in history. (xref) Its most lethal incidents included the Holocaust, the atomic bombings of Japan, the German invasion of Russia, and Japan’s attack on Pearl Harbor. In all, at least 70 million died in the conflict.

Sending Columbus to Find a Shortcut to India

In 1492, Columbus set sail to India, but ended up in the Caribbean. This would turn out to be one of the deadliest geographical mistakes in history. It set in motion a series of events that led to an almost complete genocide of an entire continent. Europeans rushed to establish colonies in the Americas, bringing with them diseases and weapons, and killing at least 90% of the indigenous population. Another horror born from Columbus’ exploration was the transatlantic slave trade, which forcibly deported millions of Africans to the Americas. Estimating the death toll from America’s colonization is extraordinarily complex, but it is undeniably an extremely high number.

What do you think was the most devastating decision in human history? Leave it in the comments section!

[a]Ton-kin https://www.merriam-webster.com/dictionary/Tonkin

[b]kwuh-RAZMEE-in https://youtu.be/92-440OR2ik?si=zoJn2fSHMF55mIPS&t=71
[c]anne loo-shan https://forvo.com/search/%E5%AE%89%E7%A6%84%E5%B1%B1/zh/
tawng https://forvo.com/search/%E5%94%90/zh/
shwen-zoang https://forvo.com/search/Xuanzong/
[d]TYE-ping https://www.dictionary.com/browse/Taiping
hong shuh-CHWEN https://forvo.com/search/Hong%20Xiuquan/ OR https://youtu.be/nSRxwx72pc0?si=VTuiR8R8Jx422jLa&t=41
NAWN-jing https://www.dictionary.com/browse/Nanjing
Qing = ching
[e]frans FERDA-nand https://www.dictionary.com/browse/Franz%20Ferdinand
gav-RILLO PRINCE-ip https://forvo.com/search/Gavrilo%20Princip/sr/
[f]vare-SYE https://www.dictionary.com/browse/versailles